In his keynote address at ISCRAT, Jerome Bruner
made reference to a study which he and his colleagues
at Oxford undertook to investigate whether 'agency' is
a construct that can be attributed to infant subjects.
He described the projection of a kindly mother-like
figure whose focus could be controled by the baby
using a mechanism like a passafier. Babys learned
that they could control the focus of the picture
with deliberate oral sucking actions.

Is anyone here familiar the original study which Bruner
referenced in his talk? A citation of that work would
be greatly appreciated.